A Parametric Model for Self-Interacting Dark Matter Halos

TL;DR

This paper introduces a parametric analytical model for self-interacting dark matter halos, calibrated with simulations, enabling predictions of halo properties across different evolutionary phases and environmental effects.

Contribution

The paper presents a universal, calibrated density profile model for SIDM halos that accounts for various evolutionary stages and external influences, based on controlled simulations.

Findings

The model accurately reproduces SIDM halo density profiles across different phases.

It requires only two parameters from CDM halos at z=0 for predictions.

The model is validated with cosmological SIDM simulations.

Abstract

We propose a parametric model for studying self-interacting dark matter (SIDM) halos. The model uses an analytical density profile, calibrated using a controlled N-body SIDM simulation that covers the entire gravothermal evolution, including core-forming and -collapsing phases. By normalizing the calibrated density profile, we obtain a universal description for SIDM halos at any evolution phase. The model allows us to infer properties of SIDM halos based on their cold dark matter (CDM) counterparts. As a basic application, we only require two characteristic parameters of an isolated CDM halo at $z=0$. We then extend the model to incorporate effects induced by halo mass changes, such as major mergers or tidal stripping, making it applicable to both isolated halos and subhalos. The parametric model is tested and validated using cosmological zoom-in SIDM simulations available in the literature.